Science Fiction Round 58: The Good Dinosaur
“The Good Dinosaur” was delightfully cute, with occasional moments of peril and “that could never happen, but… whatever, it’s cute.”
The Barrel of Fish
I feel the need to mention this first. I mean, it should be obvious, but…
… sometimes, the obvious needs saying.
- Asteroids aren’t like billiard balls bouncing off one another all the time. And also, space is big.
- Evolution doesn’t work that way. If the Chicxulub impact hadn’t happened and hadn’t killed off the dinosaurs, it’s extemely unlikely to the point of absurdity that humans would still develop. Sure, there were early proto-primates and mammals, and they would surely evolve into interesting things, but with such different environmental conditions, we can say with fair confidence that the result wouldn’t be humans.
- The lead dinosaurs are explicitly apatosauruses. Apatosaurs lived about 150 millions years ago, during the Jurassic period. Not the Cretaceous. Which means that they weren’t even around when the asteroid flashed. (Some sauropod descendents, in a group called titanosaurs, were around, but… they weren’t exactly the same.)
And now that I’ve finished party-pooping on the premise of the story, on to the more important things, like…
Where Did The Ropes Come From?
Inquiring minds want to know: how does a sauropod, with neither hands, nor prehensile tail, nor any other appendage appropriate for fine manipulation, make rope, and then tie knots in it?
We see other tools used by the sauropods, too, all of which makes me wonder how they make them. I mean, it’s going to take a lot of effort just to make the rope, and then you make a net out of it to make a trap for the human… who can’t get out of it despite having hands?
This was kind of weird.
Sharks Of The Sky
There’s a very cool scene where a couple of pterodactyls are flying so that only a part of their heads protrude through the cloud deck. They look like upside-down sharks.
But it makes me wonder: what is extinction coefficient of light passing through a cloud? In other words — how much light gets absorbed along a path of a given length through a cloud? It has to be a lot of extinction (or attenuation) for a given distance; otherwise, we’d be able to see the pterodactyls’ full bodies as well as their beaks.
I eventually found a decent review paper on the subject — according to this, a typical cloud has an extintion coefficient between 0.005 and 0.1 m^-1. Taking the high value, that means that over a depth of 1 m into a cloud, the optical depth is roughly (1 m) * (0.1 m^-1) = 0.1. Optical depth gives a rough measure of how opaque something is. At an optical depth of 1, something is essentially opaque. At much less than 1, you can still see through pretty well.
In other words, even if the pterodactyls’ beaks are 1 m long, you should still be able to see the rest of them through the cloud.
Oh, well. It looked cool.
How To Make T. Rex Friendly
I was wondering how the T. Rexes were going to be made friendly in the story. The main issue is that they’re big carnivores, which in many stories, makes them the obvious villains.
In this story, they’re essentially cattle ranchers instead. They take care of a herd, which they presumably eventually eat. Since the animals aren’t intelligent, this works just fine. They’re also put in opposition to the pterdactyls chasing Arlo (the main character) as well as a bunch of rustlers (who are raptors), giving us a chance to be sympathetic.
Still, I wonder what they mean when they say, “Let’s ride!” That makes sense for cowboys, who do actually ride horses to follow the herd. But the Rexes don’t use mounts…